Robert John Brennan (born June 7, 1962) is an American Catholic prelate who has served as Bishop of Brooklyn since 2021.

[1] Having decided to become a priest, Brennan enrolled at the Seminary of the Immaculate Conception in Huntington, New York, where he was awarded a Master of Divinity degree.

He continued in this role for Bishops James McHugh and William F. Murphy, while also providing pastoral service at St. Agnes Cathedral Parish.

[6] In August 2019, Brennan initiated with the Vatican the elevation of Saint Mary of the Assumption Church in Lancaster, Ohio, to the rank of a minor basilica.

[10] On September 29, 2021, Francis accepted the resignation of Bishop Nicholas DiMarzio of Brooklyn and named Brennan to succeed him.

[11] Brennan was installed by Cardinal Timothy Dolan on November 30, 2021, at the Co-Cathedral of St. Joseph in Brooklyn.